The Primordial Inflation Explorer (PIXIE)

Abstract

Abstract:The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). Multi-moded non-imaging optics feed a polarizing Fourier Transform Spectrometer to produce a set of interference fringes, proportional to the difference spectrum between orthogonal linear polarizations from the two input beams. The differential design and multiple signal modulations spanning 11 orders of magnitude in time combine to reduce the instrumental signature and confusion from unpolarized sources to negligible levels. PIXIE will map the full sky in Stokes I, Q, and U parameters with angular resolution 2.6 deg and sensitivity 0.2 uK per I deg square pixel. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r <1OJ\{ -3} at 5 standard deviations. In addition, the rich PIXIE data will constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to the physical conditions within the interstellar medium of the Galaxy. We describe the PIXIE instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.

The Alma Spectroscopic Survey in the Hubble Ultra Deep Field: Implications for Spectral Line Intensity Mapping at Millimeter Wavelengths and CMB Spectral Distortions

“…3, we show a comparison of various distortion signals, along with the line limits derived herein. We focus on guaranteed distortions within ΛCDM (see Chluba, 2016, for most recent overview), some of which should be detectable with future experiments, at least in terms of raw sensitivity (Kogut et al 2011). A wider range of range of energy release processes (e.g., decaying particle scenarios) is discussed in Chluba 2013 andJeong, 2014. The largest CMB expected spectral distortion is created at low-redshift by the reionization and structure formation process (Sunyaev & Zeldovich, 1972;Hu et al, 1994a).…”

Precision epoch of reionization studies with next-generation CMB experiments

“…The next decade will see further improvements in ground-based instruments designed to measure the polarization of the microwave sky with high precision. These observations would be complemented by a future space mission (e.g., Bock et al 2009;COrE Collaboration 2011;Kogut et al 2011;Matsumura et al 2013;PRISM Collaboration 2014) expected to supply cosmic variance limited measurements of the polarization spectrum at very large scales. As recently highlighted in Galli et al (2014), CMB polarization will provide an important consistency test for temperature observations and will help to pin down cosmological parameters.…”

Large area TES spiderweb bolometer for multi-mode cavity microwave detect

“…Anyway, this is an acceptable tradeoff for B-mode searches, since most of the signal is distributed at large angular scales (~10 deg) across the sky. Such a solution is adopted in the PIXIE spectro-polarimeter [6] and is currently planned as baseline field optics design for the SWIPE polarimeter [7], the high frequency (95-145-245 GHz) instrument aboard of the Large Scale Polarization Explorer balloon-borne experiment [8]. The use of multi-mode field optics is not a novelty in mm astronomy; anyway, the planned implementation into a system with strict requirements on calibration accuracy and subsystem characterization has motivated the development of a modeling-prototyping-validation pipeline which complies with the standards of a CMB polarization experiment for precision cosmology.…”